If the Lord Chancellor has his way, the heroes and villains of British TV courtroom dramas of the future may be less Kavanagh than Michael Mansfield QC, real-life suspects and 12 ordinary men and women. Following a five-week pilot in 2004, during which the Courts of Appeal made room for TV cameras, Lord Falconer is now apparently recommending that all high-profile criminal cases be eligible for broadcast in our living rooms, on the basis - broadly acceptable in the abstract - that "justice must be seen to be done".

While the legal implications of such a move are extensive and will no doubt be widely and hotly debated, the artistic implications will perhaps be less in focus - what, after all, will become of those currently responsible for the way we "see justice being done"?

At present, courtroom artists are our only visual link with the in-court action. Faces that the cameras pick out with crystal clarity on the steps of the Old Bailey are, when hearing, giving or weighing evidence inside, presented peering through a wash of unlikely pastel shades and hasty cross-hatching.

What courtroom artists do is, quite frankly, extraordinary. Not only do they produce to order, at great speed, decent likenesses of defendant, counsel and judge (but not jury), but - thanks to an Act of Parliament dating from 1925 - they are required to produce their sketches and drawings outside the courtroom from memory. So extensive are the stipulations saving us from the sight of justice being done that the vicissitudes of artistic license are considered inadequate protection: the vagaries of memory must also be drafted in to help.

One implication of the proposed use of TV cameras is that what is presumably the source of a nice-little-earner for decent artists whose skills outweigh their pretensions will dry up. For while there will probably still be a call for the services of courtroom artists, it is clear that the cases where there's real money to be made - high-profile criminal trials, or those involving celebrities - are precisely those the Falconer wants to accord TV rights.

There's another strand to this, too. For the twilight of courtroom art will mark the end of a pictorial tradition that spans the entire history of painting as an art, the tradition in which style and expression are wholly in the service of imitation of visual reality.

While it was once the case that imitation was both the mark and the measure of the artist's work - style was, when considered at all in its own right, understood in terms of the progress of perfecting representative technique - its stock has fallen greatly, its once pre-eminent place usurped, first by the Romantic idea of artistic expression, and, latterly, by contrived self-reference. Even in modern portraiture, the capturing of a likeness is secondary - who, after all, would require an artist to remind them what they looked like?

So when the cameras come rolling in to the Old Bailey, spare a thought for the squeezed courtroom artists - even now, there's only a handful of them - and the once proud tradition whose failing standard they now bear.